Pebble-mill.



M. F. ABBE.

PEBBLE MILL.

APPLICATION FILED mu. a. 1909.

Patented Dec. 28,1909.

[raven/(or .Witroesses of the mill.

Yang's. I

To all whom a mama;-

Be it known that I,MAxF. citi-.

zen. of the UnitedStates, 'residin at New' York city, Manhattam county an New York, have invented newand useful Improvements in Pebble-Mills, of which the following is a Specification. 1 1

This invention relates to a pebble Imill' provided with a taperin barrelor, shell, and means for feedlng t ground .to thewidest part I the, grinding eificiency is greatest vsov that the output of the mill is considerably increased.

In the accompanying drawingrFigure 1 is a vertical.longitudinalsectionof my iniproved pebble mill; Fig. 2, aleft hand end View thereof; broken away, on me 3-3, Fig: 1,";an 'Fig.' 4 a side elevation, par 3 Within bearings toward the ends of the mill, and-are joined at their base which thus forms thecenter of the mill. In this way shell 12. tapers from the center toward both' ends,

where it 5 tert111I1I11OIlS.'13' which en- The axis of shell 12 is arminates in hollow gage bearings 10.

' ranged in a substantially horizontal direction and the shell is rotated by means of a driving wheel 14 and a suitable power shaft (not shown). Within shell 12 are contained the usual grinding balls or pebble's15 which, owing to the tapering form of the'mill, will, during operation, have the tendency to move inward along the inclined sides of the mill toward the center thereof, '11. 6., toward that 40 P ortion of the mill which has the largest diameter. Thus, by the lateral pressure exercised upon the central pebbles, the latter will be crowdedupward to form a central bulge, as shown. Furthermore, as the balls areusually of various siz'es, the larger balls will gather at the center, the balls gradually decreasing in size "toward trunnions 13. It is evident that, owingto scribed, the grinding power of the mill is greatest at its maximum diameter and 'adually decreases toward its reduced iameters.

Means are-provided forfeeding the ma terial to be ground tothe mill at that portion thereof which has ,the greatest grindin g capacity,

e material to be: of the she'llwhere 3 across section,- artly tly in' section,',of. a,

1 .16, w1th the inlet end 0 Within this boss may,

' upon the reduced end of the mill, s

- as m"... that the na i be ground are subjected to'fthe most forceful grinding action, such action gradually 'decreasing with the gradual reduction of the particles.- In this way the power f-ofthe {mill is utilized to great advantage. The 'means for efiecting the 3 to be ground are as follows Upon one of the reduced ends of shell 12 is fitted a cylinal pair of chambers 18,

20 of chamber isms an annular opening 21 for-admitting the feed pipe 22,, which 'is with chamber 18 by an: opening'24 :of-partitijon 17. The inner 'convolute of spiral 23 communicates, through 0 ening 25' of casing .26 .adapted to convey a spiral conveyer the material to .be'

- ramm Dec. 28,1909.

feed of the particles 7 dri cal casing 16 div ded by partition 17 int 19. The. outer wall the outer convoluteLof which communicates ground to a peripheral inlet opening formed 1 at the center -,or greatest diameter of the mill. Conveyer 26 is coiled partly around shell 12 and its flanged outlet end is bolted to a boss 7 formed on the center of such shell.

28 which prevents pebbles 15 from dropping into the conveyer. By fitting casing 16 ace will be e'conomized and the diameter 0 the latter will not be unduly increased, while the material to be ground will be nevertheless fed to its widest portion. Within each of the hollow trunnions 13 is removably fitted a tapering discharge nozzle 29, the outer plate 30 of which is bolted at 31 to a flange of the trunnion. At its inner end, nozzle 29 is provided with a grate 32 which permits the discharge of the round material, while confining the balls the conditions 1 Within shell 12. c In use, the-material to be ground will, from tube 22 and chamber 18, be fed to be contained a grate spiral 23 which delivers it through conveyer that is to say,'at its greatest ends. Here too, the material to be ground is 2 fed into the widest portion of the shell through conveyer 26, to pass toward thereduced discharge end thereof.

I claim:

1. A pebble mill comprising a coniform shell having a peripheral inlet opening at the widest portion thereof, a pair of snpporting bearings, means for axially rotating the shell, grinding bodies inclosed Within the shell, a casing encompassing the shell, a spiral conveyer within the casing, and means for connecting the casing with the inlet opening.

2. A pebble mill comprising a coniform shell having a peripheral inletopening at the widest portion thereof, a pair of supporting bearings, means the shell, grinding bodies inclosed within the shell, a casing encompassing a reduced section of the shell, in the casing, and a feed spiral connecting the casing with the inlet opening.

3. A pebble mill comprising a coniform shell having a peripheral inlet opening at the widest portion thereof, a pair of trunnions, one of which is hollow, means for axially rotating the shell, grinding bodies for axially rotating I a spiral conveyer withinclosed within the shell, a casing encompassing the shell, a spiral conveyer within the casing, and means for connecting the casing with the inlet opening.

4. A pebble mill comprising an axially r0- tatable shell provided with, a peripheral inlet opening at a point intermediate its ends, said shell having discharge openings on 0pposite sides of the inlet opening, grinding means inclosed within the shell, and means for feeding the material to the inlet opening; whereby the ground material will be free to flow Without obstruction in opposite directions to the discharge openmgs.

5. A pebble mill comprising a coniform peripheral shell having a peripheral inlet opening in its Widest portion,

means for axially rotatmg the same,

grmding meansinclosed Within the shell, and means for feeding the mat'erial into the peripheral inlet opening.

Signed by me at New York city, (Manhattan,) N. Y., this 8th day of March, 1909.

- MAX F. ABBE. Witnesses:

FRANK v. BRIEsEN, EDWARD SCHORR. 

